An electric compressor refers to a compressor including a compression unit configured to compress target material in a housing, and an electrically-driven unit, i.e., a motor, configured to drive the compression unit. The electric compressor includes a power source terminal configured to receive power for driving the built-in motor from an external device. The power source terminal includes an electrically connection pin provided for electrical connection with a controller provided in the compressor housing.
In the case of a compressor using a 3-phase motor, three electrical connection pins are provided. Typically, the three electrical connection pins are disposed parallel to each other around a stator. The electrical connection pins are disposed to protrude out of a motor housing, and are coupled with terminals provided in the controller. Therefore, three through holes are formed parallel to each other in the motor housing so that the three electrical connection pins pass through the respective through holes.
Pressure in the compressor is changed depending on the kind of refrigerant to be used. If refrigerant such as CO2 is used, the interior of the compressor is maintained at a super-high pressure because a refrigeration cycle is operated in a supercritical region. In the case where super-high pressure refrigerant is used, the importance of sealing increases compared to that of the other cases. If, as described above, the three electrical connection pins are disposed parallel to each other, there is the possibility that excessively high stress is applied to regions between the through holes.
Such excessively high stress causes deformation of the housing around the through holes, thus leading to an increase in possibility of leakage of refrigerant.
To avoid the foregoing problem, there is need to reinforce the housing, e.g., by changing the material of the housing or increasing the thickness of the housing. However, it is not easy to use this method because it causes increases in the production cost and the weight of a product.
Furthermore, an assembly process is typically performed as follows: forming a single large through hole in lieu of the three through holes which are separately formed; and inserting, into the single through hole, a mounting plate to which the three electrical connection pins are fixed parallel to each other. However, in this structure, the higher the pressure in the compressor, the higher the possibility of removal of the mounting plate from the correct position. Thus, there is a problem in that the reliability of the product is reduced.